Sunday, September 11, 2005

I'll be giving a talk at the Wellington Common Lisp User Group meeting this Friday. It'll be about the Scheme continuation based web server I use at work, how I managed to use Lisp in our primarily Java based development shop, etc. Should be fun. 2:50:30 PM

The framerate synchronisation problem I mentioned previously is now fixed. The Space Invaders emulator now runs at a playable speed. I've also added some colour overlays so bases are green, the UFO is red, etc. A screenshot is here. The code itself has been re-organised a little so that the space invaders specific code is seperated from the generic 8080 emulation code. The space invaders object delegates to the 8080 object and specializes generic words for displaying video and handling the input and output ports. This should make supporting other ROM's, and other 8080 architectures easier. There is one small bug in the DAA instruction which converts the accumulator register into BCD format. It appears to be used for displaying the score and sometimes the score displays incorrectly. I'll be fixing this in the next update. I hope to get sound added eventually too. 2:27:38 PM